1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // <array>
11 
12 // reference front();
13 // reference back();
14 // const_reference front(); // constexpr in C++14
15 // const_reference back(); // constexpr in C++14
16 
17 #include <array>
18 #include <cassert>
19 
20 int main()
21 {
22     {
23         typedef double T;
24         typedef std::array<T, 3> C;
25         C c = {1, 2, 3.5};
26 
27         C::reference r1 = c.front();
28         assert(r1 == 1);
29         r1 = 5.5;
30         assert(c[0] == 5.5);
31 
32         C::reference r2 = c.back();
33         assert(r2 == 3.5);
34         r2 = 7.5;
35         assert(c[2] == 7.5);
36     }
37     {
38         typedef double T;
39         typedef std::array<T, 3> C;
40         const C c = {1, 2, 3.5};
41         C::const_reference r1 = c.front();
42         assert(r1 == 1);
43 
44         C::const_reference r2 = c.back();
45         assert(r2 == 3.5);
46     }
47 
48 #if _LIBCPP_STD_VER > 11
49     {
50         typedef double T;
51         typedef std::array<T, 3> C;
52         constexpr C c = {1, 2, 3.5};
53 
54         constexpr T t1 = c.front();
55         static_assert (t1 == 1, "");
56 
57         constexpr T t2 = c.back();
58         static_assert (t2 == 3.5, "");
59     }
60 #endif
61 
62 }
63